/*
 * The contents of this web application are subject to the Mozilla Public License Version 
 * 1.1 (the "License"); you may not use this web application except in compliance with 
 * the License. You may obtain a copy of the License at http://www.mozilla.org/MPL/.
 * 
 * Software distributed under the License is distributed on an "AS IS" basis, 
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License 
 * for the specific language governing rights and limitations under the License.
 * 
 * The Original Code is owned by and the Initial Developer of the Original Code is 
 * Composite A/S (Danish business reg.no. 21744409). All Rights Reserved
 * 
 * Section 11 of the License is EXPRESSLY amended to include a provision stating 
 * that any dispute, including but not limited to disputes related to the enforcement 
 * of the License, to which Composite A/S as owner of the Original Code, as Initial 
 * Developer or in any other role, becomes a part to shall be governed by Danish law 
 * and be initiated before the Copenhagen City Court ("K�benhavns Byret")            
 */

using System;
using System.Collections.Generic;
using System.Configuration;
using System.Linq;
using Composite.C1Console.Commands.Plugins.ConsoleCommandHandler.Runtime;
using Composite.C1Console.Events;
using Composite.Core.Collections.Generic;
using Composite.Core.Configuration;

namespace Composite.C1Console.Commands.Foundation.PluginFacades
{
    class ConsoleCommandHandlerPluginFacade
    {
        private static ResourceLocker<Resources> _resourceLocker = new ResourceLocker<Resources>(new Resources(), Resources.DoInitializeResources);


        static ConsoleCommandHandlerPluginFacade()
        {
            GlobalEventSystemFacade.SubscribeToFlushEvent(args => Flush());
        }

        internal static IConsoleCommandHandler GetConsoleCommandHandler(string pluginName)
        {
            IConsoleCommandHandler plugin;

            var resources = _resourceLocker.Resources;

            if (!resources.ConsoleCommandHandlers.TryGetValue(pluginName, out plugin))
            {
                return null;
            }

            return plugin;
        }

        private static ConsoleCommandHandlerSettings GetSettings()
        {
            var configuration = ConfigurationServices.ConfigurationSource;

            if (configuration == null) return null;

            return configuration.GetSection(ConsoleCommandHandlerSettings.SectionName) as ConsoleCommandHandlerSettings;
        }


        public static bool HasConfiguration()
        {
            return GetSettings() != null;
        }


        private static void Flush()
        {
            _resourceLocker.ResetInitialization();
        }



        private static void HandleConfigurationError(Exception ex)
        {
            Flush();

            throw new ConfigurationErrorsException(string.Format("Failed to load the configuration section '{0}' from the configuration.", ConsoleCommandHandlerSettings.SectionName), ex);
        }



        private sealed class Resources
        {
            ConsoleCommandHandlerFactory Factory { get; set; }
            public IReadOnlyDictionary<string, IConsoleCommandHandler> ConsoleCommandHandlers { get; private set; }

            public static void DoInitializeResources(Resources resources)
            {
                var settings = GetSettings();
                if (settings == null) return;

                try
                {
                    var factory = resources.Factory = new ConsoleCommandHandlerFactory();

                    resources.ConsoleCommandHandlers = settings.ConsoleCommandHandlers.ToDictionary(data => data.Name, data => factory.Create(data.Name));
                }
                catch (Exception ex)
                {
                    if (!(ex is ArgumentException) && !(ex is ConfigurationErrorsException)) throw;

                    HandleConfigurationError(ex);
                }
            }
        }
    }
}
